Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosurehol. It adds meaningful context: it uses DVF recorded sale prices rather than listings, returns a median price per square metre and the sample size for reliability judgment, and discloses the per-call cost and payment method. It does not explain failure modes, address normalization, or coverage limitations, but the core behavior is well disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The primary purpose is front-loaded in the first sentence, the second sentence explains outputs and reliability cues, and the pricing note is appended without bloating the description. Every sentence adds value and there is no redundant repetition of the tool name or schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the main input of address/surface, the data source, the output components, and the cost, which is helpful given there is no output schema. However, it is incomplete for a required parameter 'type' and does not specify units (e.g., square metres), output format, currency, or error conditions, leaving notable gaps for an autonomous agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate by documenting the three required parameters. It explains 'adresse' and 'surface' in prose, but it fails to mention the required 'type' parameter at all, leaving the agent without guidance on what values are expected or how it affects the estimate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Estimate the market value') and a precise resource ('a French property from its address and surface area'), then distinguishes the tool from listing-based approaches by grounding it in the DVF open dataset of recorded sale prices. This makes the tool's role clear and differentiates it from siblings that likely source from listing sites like fr_seloger or fr_leboncoin.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies the tool should be used when estimating a French property's value from address and surface data, especially when actual sale prices are preferred over asking-price listings. However, it does not explicitly state when to use this tool over alternatives such as fr_valorisation or fr_analyse-immo, nor does it give any 'when not to use' guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.